1. Field of the Invention
This invention relates to poly(alkylene carbonate) polyahls.
2. Description of the Background
Poly(alkylene carbonate) polyahls are randomized polymers containing active hydrogen end groups and alkylene carbonate moieties and ether moieties such as di- and higher polyalkylenoxy units. An alkylene carbonate moiety is a repeating unit comprising an alkylene group bound to a carbonate moiety. Some of the known poly(alkylene carbonate) polyahls are non-ionic surfactants.
In 1978, DE No. 2,712,162 to Stuehler disclosed non-ionic surfactants containing carbonate moieties in the backbone. A variety of surfactants have been prepared by Langdon and described in a series of patents. U.S. Pat. No. 4,072,704 described the coupling of polyethylene glycols and polypropylene glycols with either dialkyl carbonates or formaldehyde to give materials with surface active properties. In U.S. Pat. No. 4,353,834, it was described how long chain amides or sulfonamides have been coupled with hydrophilic polyglycols using dialkyl carbonates or esters of dicarboxylic acids to give materials with surface active properties. This work was extended in U.S. Pat. No. 4,504,418 to include polyoxyalkylene polymers and monofunctional aliphatic, aromatic or aliphatic-aromatic alcohols coupled by alkyl carbonates or esters of dicarboxylic acids to give materials with surface active properties.
U.S. Pat. No. 4,330,481 to Timberlake et al. described the preparation of surfactants by reacting alcohols or alcohol ethoxylates with ethylene carbonate. These products were then further reacted with ethylene oxide to produce different surface active materials as reported in U.S. Pat. No. 4,415,502. The preparation of surfactants and functional fluids by reacting alcohols, phenols or carboxylic acids (or their alkoxylated derivatives) with alkylene carbonates or alkylene oxides and carbon dioxide was described in U.S. Pat. No. 4,488,982 to Cuscurida.
U.S. Pat. No. 4,382,014 to Sakai et al. described the preparation of surface active materials by reacting alcohols, carboxylic acids or primary or secondary amines containing four or more carbon atoms or substituted phenols with alkylene carbonates in the presence of an -ate complex of a metal of Group II, III or IV of the Periodic Table having at least two alkoxyl groups.
Low molecular weight polyoxyethylene glycol monomethyl ethers have been coupled using phosgene or alkyl carbonates to give materials useful in formulating brake fluids and as synthetic lubricants, as disclosed in U.S. Pat. No. 3,632,828. The coupling of monofunctional alcohols, phenols or their ethoxylated derivatives using diphenyl carbonate to give surfactants was disclosed in U.S. Pat. No. 3,332,980.
In 1981, U.S. Pat. No. 4,267,120 to Cuscurida et al. described polyester polycarbonates terminated with hydroxyl groups obtained by the reaction of a cyclic organic acid anhydride, a 1,2-epoxide, carbon dioxide and a polyhydric compound in the presence of a basic catalyst. The Cuscurida et al. polymers are hydroxy-functional materials. In the Cuscurida et al. patent, the cyclic anhydride is present during polycarbonate preparation and is therefore chemically incorporated into the polymeric backbone.
The applications of non-ionic poly(alkylene carbonate) polyahl surfactants are limited due to their very poor water solubility and wetting times. In addition, these non-ionic surfactants also form poor foams evidencing poor foam stability, which in specific instances may be an advantage or a disadvantage depending on the particular application. Further, fairly high concentrations of these non-ionic surfactants are required before any surface active properties, like lowering the surface tension of water, are evidenced.
Unfortunately, conventional non-ionic poly(alkylene carbonate) polyahls are not as efficient surfactants as are desired for certain applications. Therefore, there still is a need for more efficient poly(alkylene carbonate) polyahl surfactants which retain the beneficial characteristics of conventional poly(alkylene carbonate) polyahls such as biodegradability.